For quite some we all used to use websites. And one some of these websites are creating accounts and this requires us to use passwords. From technical point of view there is nothing that prevents us using any character that you can type on keyboard including Chinese and Japanese. And the more characters allowed the safer password is. Imaging that password only allows 3-character passwords. For only lower-case English letters there will be 26*26*26 = 17,576 combinations. If upper case letters are also allowed, then you have 52*52*52 = 140,608 combinations and that is 8 times more. But if Chinese characters are also allowed then 50052 * 50052 * 50052 and that is 125,390,405,740,608 combinations.

But as you can imagine